Sometimes I think it is easy to discount the routine, daily work we do as mothers as secondary in our efforts to help build the kingdom of God. Afterall, we have visiting teaching to do, callings to fill (and magnify!), meetings to attend, etc.... But here is a quote from Dallin H. Oaks that I found very grounding (emphasis added):
"'Seek first to build up the kingdom of God' means to assign first priority to God and His work. The work of God is to bring to pass the eternal life of His children (see Moses 1:39), and all that this entails in the birth, nurturing, teaching, and sealing of our Heavenly Father's children. Everything else is lower in priority" ("Focus and Priorities," Ensign, May 2001, 83-84).
Obviously, our work as mothers can coexist with other things that might be asked of us to help build the kingdom (and nurturing/teaching all of God's children is certainly included), but it's comforting to know that the time and effort spent with our little ones- no matter how mundane- is the best thing we can be doing above all else.
So go out and wipe those snoozy noses with pride!